A lithographic apparatus is a machine that applies a desired pattern onto a substrate, usually onto a target portion of the substrate. A lithographic apparatus can be used, for example, in the manufacture of integrated circuits (ICs). In that instance, a patterning device, which is alternatively referred to as a mask or a reticle, may be used to generate a circuit pattern to be formed on an individual layer of the IC. This pattern can be transferred onto a target portion (e.g. comprising part of, one, or several dies) on a substrate (e.g. a silicon wafer). Transfer of the pattern is typically via imaging onto a layer of radiation-sensitive material (resist) provided on the substrate. In general, a single substrate will contain a network of adjacent target portions that are successively patterned. Known lithographic apparatus include so-called steppers, in which each target portion is irradiated by exposing an entire pattern onto the target portion at one time, and so-called scanners, in which each target portion is irradiated by scanning the pattern through a radiation beam in a given direction (the “scanning”-direction) while synchronously scanning the substrate parallel or anti-parallel to this direction. It is also possible to transfer the pattern from the patterning device to the substrate by imprinting the pattern onto the substrate.
U.S. Pat. No. 6,392,800 relates to an optical arrangement wherein an entering beam is converted into an exiting beam having a total cross section of radiation which is linearly polarized essentially in the radial direction by rotation. U.S. Pat. No. 6,392,800 is incorporated herein by reference.
U.S. Pat. App. No. 2001/0019404 relates to a method and arrangement for microlithographic projection exposure at high aperture which achieves a contrast increase by polarization of radiation perpendicular to the plane of incidence on the resist. U.S. Pat. App. No. 2001/0019404 is incorporated herein by reference.
U.S. Pat. No. 6,310,679 describes a lithographic apparatus in which a coherence reducing member is provided in the optical train between the mask and the substrate. The coherence reducing member may be a polarization control member for changing the polarization state of the radiation.